When keratometer mires are only clear when the wearer blinks, what does this indicate about the lens fit?

When the keratometer mires are only clear during a blink, it indicates that there is likely inadequate movement of the contact lens on the eye's surface. A tight lens fit does not allow for proper fluid exchange and can result in the lens adhering too closely to the corneal surface. This phenomenon often causes distortion of the mires, making them appear only clear with the extra movement created by blinking, as the blink momentarily repositions the lens on the eye.

In a tight fitting lens scenario, the lack of appropriate movement can also lead to discomfort for the wearer over time. Optimal lens fit typically allows for some movement with blinks and would ensure consistent clarity of the mires without assistance from blinking, proving that a tight fitting lens does not permit this ideal state.